Considerable literature exists on the role of dietary NaCl on taste and salt intake as well as on blood pressure regulation of adults. Recent studies indicate, however, that NaCl levels in the diet may have its most profound effect early on ontogenesis when there are important developmental changes in the neuroendocrine mechanisms that control sodium and blood pressure regulation. These neuroendocrine mechanisms appear to be plastic subject to modification by dietary experience particularly during periods of rapid developmental change. There is substantial evidence, for example, linking the NaCl intake of pregnant and lactating rat mothers with changes in the NaCl intakes, blood pressures, and in the sodium taste system of their adult offspring. Enhanced or restricted experience with dietary Na Cl through the maternal diet can influence the offsprings; NaCl intake, blood pressure, and sodium taste system. The aims of the Program Project are to examine the consequences and mechanisms of early salt intake on taste and blood pressure, Emphasis will be placed on the integration of behavioral, physiological, morphological, and neurological approaches in the study of male and female Sprague-Dawley rats. The aims of Project 1 will be to characterize the effects of maternal NaCl intake on the offspring's taste and blood pressure reactivity to NaCl. Project 1 will also obtain a detailed analysis of ingestive behavior and blood pressure to gain insight not only on how blood pressure changes over the circadian cycle due to perinatal salt intake, but how blood pressure changes in relationship to feeding, particularly in relationship to NaCl intake. In Project 2 sophisticated psychophysical procedures will be used to examine changes in taste thresholds in rats of various ages and maternal histories. Project 2 will also define the spectrum of specificity induced by the different perinatal diets. The aim of Project 3 will be to examine various physiological and neurochemical mechanisms that may underlie the blood pressure and behavioral changes examined in other two Projects. A major focus in Project 3 will be on the renin-angiotensin system. The overall Program will provide new basic information about the consequences and mechanisms of early exposure to known amounts of NaCl on taste and blood pressure in an important animal model.